|
Items in cart [1] |
Questions? Call 888-624-8373 |
|
||||||||||||||||
|
||||||||||||||||
The following HTML text is provided to enhance online readability. Many aspects of typography translate only awkwardly to HTML. Please use the page image as the authoritative form to ensure accuracy. THE SUBCOMMITTEE’S RISK ASSESSMENT PROCESSRisk assessment is the process of quantitatively determining the likelihood of adverse effects resulting from exposures to FR chemicals. The risk assessment paradigm used in this report and widely acknowledged by the U.S. scientific community to be the current standard used in industrial risk management and public policy settings was first articulated by the U.S. National Research Council in its report, Risk Assessment in the Federal Government: Managing the Process (NRC 1983). In a sequel entitled Science and Judgment in Risk Assessment (NRC 1994), the National Research Council defined major elements in the estimation of health risks and placed the process within contexts of managing such risks. Among the elements elaborated in detail are (1) the values and limitations of default assumptions and the circumstances under which they should be replaced with empirical findings; (2) the importance of understanding the mode of toxic action of a compound to provide increased accuracy in defining the presence of hazards to human health; (3) the role of variability in human response as a basis for deciding the degree of health protection for susceptible subpopulations; and (4) aggregation of exposures and risks from all sources of exposure so as to provide realistic estimates of risk to specific groups of individuals. In this report, health risks are characterized for potential effects in the body after repeated and prolonged exposures to FRs. Although acute toxicity information was reviewed, it was not used in developing risk assessments because chronic exposure data are more relevant. The four basic steps of risk assessment process applied to FRs are hazard identification, dose-response assessment, exposure assessment, and risk characterization. Each is described below. Hazard IdentificationIn the hazard identification step, a determination was made of causal relationships that exist between exposure to an FR and its adverse health effects. It involves gathering and critically evaluating toxicity data on the types of health effects that might be produced by an FR and on the conditions of exposure under which adverse effects are produced. Such an evaluation requires the development of the weight of all the evidence related to the toxicity of an FR. Toxicity data are derived from observations of humans (epidemiological studies, clinical findings, and case reports), from investigations of laboratory animals (most often rodents), and from in vitro studies.
|
|
|||||||||||||||
